NAME:  pitchfx.dat
TYPE:  Population  
SIZE:  66269 observations on 29 variables

DESCRIPTIVE ABSTRACT:
Individual pitch data for twenty starting pitchers in the 2009 Major League Baseball season.  Ten 
of the pitchers are of the "elite" type (each has been nominated for the main pitching award 
(the Cy Young award) in recent seasons) and the remaining pitchers are "non-elite".

SOURCE:
This pitch by pitch data together with extra information such as the inning, batter, and result 
of the plate appearance is available for free from the Major League Baseball website
http://gd2.mlb.com/components/game/mlb/.  The author downloaded data from the xml files for 20 
starting pitchers in the 2009 season.  Data was collected for each of the games that these pitchers 
played and the files were combined to create a single data file.  

FORMATS:
The play by play dataset is available both as a data file "pitchfx.dat" 
and a R workspace "pitchfx.Rdata".  Tab characters are used to separate variables in the data file.

READING INTO R:
The play-by-play data file can be read into R by the command
pitchdata=read.delim("http://bayes.bgsu.edu/baseball/pitchfx.dat")

VARIABLE DESCRIPTIONS:
Each row represents information about a given pitch during a particular game.

pitcher		last name of the pitcher
game			game number
id			code identifying the pitcher  
inning		inning of game 
num			number of batter  
batter		code identifying the batter  
stand		side of batter (L or R) 
b_height		height of batter (feet and inches)
p_throws		side of pitcher (L or R)
des			detailed description of play at end of plate appearance
event		brief description of play at end of plate appearance 
brief_event	same as event 
des2			pitch outcome (called strike, ball, in-play, etc) 
type			pitch code  (B, S, or X (in play))
pfx_z		deviation (in inches) of pitch trajectory in vertical location
px			pitch location in x direction as it crosses home plate 
pz			pitch location in z direction as it crosses home plate
start_speed	starting speed of pitch in mph
end_speed		speed of pitch crossing plate in mph
sz_top		top of strike zone in feet
sz_bot		bottom of strike zone in feet
pfx_x		deviation (in inches) of pitch trajectory in horizontal location
count		current pitch count
new.count		new pitch count
value		pitch value using linear runs measure
pitch_type	pitch classification
new.count.type	PA event or new count
count.adv		classification of count as pitcher or batter or neutral count

Missing values are denoted with NA.

PEDAGOGICAL NOTES:
Using the Pitch F/X dataset, one can explore the pitching tendencies of the twenty pitchers.  
What pitches do they throw, what is the movement and speed of these pitches, and where are they 
thrown relative to the strike zone?  Are particular pitches more successful in getting the batter 
to swing and miss?  How do the pitchers differ with respect to pitch type and the speed that 
they throw the pitches?  There  are nine pitchers in this dataset that can be regarded as 
``elite" since they received votes for the Cy Young award given to the best pitcher in the 
National League and the American League.  What distinguishes these elite pitchers from the 
remaining ``non-elite" pitchers?

REFERENCES:
Albert, Jim, Baseball Data at Season, Play-by-Play, and Pitch-by-Pitch Levels
Alan Nathan, MLB Extended Gameday Pitch Logs
http://webusers.npl.illinois.edu/~a-nathan/pob/tracking.htm

SUBMITTED BY:
Jim Albert
Department of Mathematics and Statistics
Bowling Green State University
Bowling Green, OH  43403
albert@bgnet.bgsu.edu